Groovy annotation dynamic

import javax.xml.bind.annotation.XmlElement

@GroovyASTTransformation(phase = CompilePhase.CANONICALIZATION)
class WebserviceAnnotationModifier implements ASTTransformation {
    @Override
    void visit(ASTNode[] astNodes, SourceUnit sourceUnit) {

        if (!astNodes) return
        if (!astNodes[0] || !astNodes[1]) return
        if (!(astNodes[0] instanceof AnnotationNode)) return
        if (!(astNodes[1] instanceof ClassNode)) return
        ClassNode node = (ClassNode)astNodes[1]
        List fields = node.getFields()
        fields.each {FieldNode field ->
            field.addAnnotation(ClassHelper.make(new XmlElement.DEFAULT()));
        }
    }
}

@Retention(RetentionPolicy.SOURCE)
@Target([ElementType.TYPE])
@GroovyASTTransformationClass(classes =[WebserviceAnnotationModifier])
public @interface WebresourceAnnotation{}

 @WebresourceAnnotation
   class TestPerson{
        String name;
        String lastName;
        int Age
    }